Yarn-forwarding apparatus and process

ABSTRACT

A yarn-forwarding apparatus which comprises a housing having an internal bore passing therethrough. The bore is divided into sections having different diameters which are connected by a converging surface. A hollow element is mounted in the bore of the housing and has an internal bore of different diameters which are connected by a converging surface. The end of the hollow element which is mounted in the bore of the housing is provided with a converging outer surface having less taper than the converging surface of the internal bore of the housing and a first annular converging chamber is formed between the converging surfaces of the housing and the hollow element. A hollow tube is mounted in the bore of the hollow element. The end of the hollow element which is mounted in the bore of said hollow element is provided with a converging outer surface having less taper than the converging surface of the internal bore of the hollow element and a second converging chamber is formed between the converging surfaces. Inlet means is provided in the housing and the hollow element for introducing a gaseous medium into the first and second converging chambers.

P r i r r it nrten @tntes ll ntent n 1 meshes Harrison iieh. 23%. 11932.2.

[54} hfililtN-WMNWARJMNG APPAWtAThIfi AND [72] inventor: Devin M. ll-ilnrrison, Ch ter, V A yarn-forwarding apparatus which comprises a housing having an internal bore passing therethrough. The bore is divided [73] Asslgnee' g af {:mmflmfl Qmmmmn New York into sections having different diameters which are connected by a converging surface. A hollow element is mounted in the [22} Filed: July Bill, 1969 bore of the housing and has an internal here of different diameters which are connected by a converging surfnce. 'E'he [211 App! M6561 end of the hollow element which is mounted in the hone oi the housing is provided with a. converging outer surface having [52] US. til... ..226/97, 28/ 1.4, 226/7 less taper than the converging surfiacc of the internal bore of 653i 17/32 the housing and a first annular converging chanaher is formed [58] Field mi tlearch ..226/97, 7; 23/14; 57/90 between the converging surfaces of the housing and the ho!- low element. A hollow tube is mounted in the bore of the hol- {561 melm'wms low element. The end of the hollow element which is mounted UNITED STATES PATENTS n the bore of said hollow element is provided with a convergmg outer surface having less taper than the converging surface 3,485,428 12/ 1969 Jackson ..226/97 of the internal bore of the hollow element and a second con- 3,295.l62 1/1967 Forceville ....28/ 1.4 X verging chamber is formed between the converging surfaces. 3,330,242 4/ 1963 Ri hm n 6t 81 X Inlet means is provided in the housing and the hollow element for introducing a gaseous medium into the first and second Primary Examiner-R1chard A. Schacher converging h be Assistant Examiner-Gene A. Church Attorney-Roy l-l. Massengill 1111 Claims, 3 Drnwing li ignres 22 23 l4 A 5 i 4 7 h I3 24 317 .1 my m u l r W N 2 26 |5 s: I2 32 PATENTEOFEB29 I972 3,645,431

smears 32 8 I6 w 0: I50 S l q g g 12 5 a Q 2 v; Q a 8 a a o INNER- B00) 4 WITHDRAWN FROM INNER MOST POSITION IN HOUSING UNIT 2, TURNS OUTWARD 0N THREAD MEANS 6.

INVENTOR.

- DA V/O H. HARRISON BYMX A TORNE Y PAIENTEnFEm I972 3, 645,431

SHEET 3 OF 3 O I/? I I //2 2 2 [/2 INNER-BODY 4 WITHDRAWN FROM INNER- MOST POSITION IN HOUSING UNIT 2, TURNS OUTWARD ON THREAD MEANS 6.

INVENTOR.

DA VID M. HARRISON TURN llACliGllOUl lD UP THE lhli/ENTHUN This invention relates to multistage yarn forwarding or manipulating apparatuses and, in particular, to a method or process for piclting up a running length of yarn and maintain ing the yarn under tension until it can be transferred to a yarn takeup or other winding apparatus.

in the forwarding natural or synthetic yarns, it is frequently desirable that the yarn be collected temporarily by an auxiliary apparatus rather than by the regular collecting or windup apparatus. A typical application for such an auxiliary apparatus is to transfer yarn to a waste collector during dotting operations.

Many textile-processing operations require that adequate tension be maintained on the yarn when transferring it from one position to another. it is also important that yarn tension should not be pennitted to remain at a reduced level for even a short period of time. When apparatuses of the prior art first engage a running length of yarn, they piclr up the yarn by generation of sufficient suction.

While the yarn is being engaged and is moving into the apparatus, the tension on the yarn is unavoidably reduced. The duration of this reduced tension period and the magnitude of the tension during this reduced tension period depend on the adjustment of the orifice of the yarn-forwarding apparatus. In fast-running processes, that is where the yarn is running at speeds such as 2,000 to 3,000 yards per minute, it is important the tension on the yarn during the yarn engagement period he as great as possible and the duration of the reduced tension period be as short as possible. For this yarn-engaging function of a yarn-forwarding apparatus, it is thus important to adjust the orifice of the apparatus to a highsuction condition. lEngagement of the yarn is considered to be complete when the free end of the yarn has travelled sufficiently far into the yarntorwarding apparatus for substantially full tension to be exerted on the yarn.

A further function of a yarn-forwarding apparatus is to provide a suitably high tension on the yarn after engagement of the yarn is completed. in fast-running processes, as described above, yarn tensions whichwere suitable at slower running speeds are no longer suitable and serious processing problems, such as threadline breakdown in the processing equipment, arise if the yarn tension is not at a suitably high level. For effective performance of this yarn-tensioning function, it is thus important to adjust the orifice of the apparatus to a high-tension condition.

The prior art discloses only single-stage yarn-forwarding apparatuses and processes wherein the suction stage and tension smge are the same unit. in such apparatuses and processes, it is impossible to control suction and tension simultaneously and independently. The characteristics of such apparatuses and processes are such that only a high-suction and low-tension condition or a high-tension and lOWSUCIiOll condition or a compromise between the two can be achieved simultaneously. in none of these apparatuses and processes can high suction and tension be achieved simultaneously and independently.

Further prior art discloses single-stage yarn-forwarding apparatuses and processes whereby adjustment from a high-suction to a hightension condition may rapidly be made after the operator has perceived that engagement of the yarn is complete. These apparatuses and processes suffer the disadvantage in that the reaction or delay time of the operator or equipment which exists before the operator can apply high tension is sufficient to cause threadline breakdown or other processing problems at high speeds.

it has now been discovered that the suction and the tension stages of a ya n-forwarding apparatus can be simultaneously and independently controlled by means of a multistage apparatus wherein at least one of the stages produces suction and at least one of the stages produces tension on the yarn. in such an apparatus, the suction stage and the tension stage are ,b lidfll SUMMARY 0i? "filth llhl t liltl'iltjl hl In accordance with the present invention there provid d a yarn-forwarding apparatus which comprises housing having an internal bore passing therethrough. "the here is divided into sections having different diameters which are connected by a converging surface. A hollow element is mounted in the bore of the housing and has an internal bore of different nature which are connected by a converging surface. The end of t hollow element which is mounted in the bore of the housing is provided with a converging outer surface having less taper than the converging surface of the interned bore of the housing and a first annular converging chamber is formed between the converging surfaces of the housing and the hollow element. 1% hollow tube is mounted in the bore of the hollow element. "the end of the hollow tube which is mounted in the bore of said hollow element is provided with a converging outer surface having less taper than the converging surface of the internal bore 'of the hollow element and a second converging chamber is formed between the converging surfaces. inlet means is provided in the housing and the hollow element for introducing a gaseous medium into the first and second converging chambets.

The yarn-forwarding apparatus of the present invention can be provided with means for adjusting the positions of the hollow element and the hollow tube to vary the cross-sectional areas of the first and second annular converging chambers. in addition, the yarn-forwarding apparatus of the present invention can be provided with separate means for independently adjusting the respective positions of the hollow element and hollow tube to vary the cross-sectional area of the first and second annular converging chambers.

in further accordance with the present invention there is provided, when operating a preferred embodiment of the present invention, a method or process for simultaneously imposing high suction and high tension upon a yarn to cause forwarding of the yarn which comprises introducing or yarn into a restricted area and directing a first and a second stream of traveling at a high velocity upon separate portions of the yarn. The first and the second streams of gas can be introduced either independently or from a single supply inlet. hlllien a sin gle supply inlet is employed, the gas can be introduced at a rate of about 20 to 80, preferably about 30 to 60, s.c.f.m. and at a pressure of about 50 to 250, preferably about to 200, p.s.i.g.

The velocity of the first and second streams of gas can be controlled independently wherein the first stream of gas is in troduced at a rate of about 5 to 25, preferably about ill to ill), s.c.f.m. and at a pressure of about 50 to 250, preferably about 80 to 200, p.s.i.g. and the second stream of is introduced at a rate of about 15 to 55, preferably about 20 to 40, softer. and at a pressure of about 50 to 250, preferably about lit) to 200, p.s.i.g.

The first stream of gas imposes a suction force upon the yarn and the second stream of gm imposes a tension force upon the yarn. The suction force upon the yarn can range from about 12 to 29, preferably about 20 to 29, inches of mercury and the tension force upon the yarn can range from about 0.07 to 0.25, preferably about 0.1 to 0.25, grams per denier. The suction force on the yarn can be most conveniently measured by attaching a manometer to the yarn inlet means of the yarn-forwarding apparatus.

The rate of yarn forwarding through the apparatus of the present invention using the method or process of the present invention can range from about 1,000 to 4,000, preferably about L500 to 3,000, yards per minute.

The gas which is used in the present invention can be any inert gas, for example, carbon dioxide, nitrogen and the litre, but preferably is air at about room temperature.

The term yarn as used in describing the present invention is not limited to the conventional textile definitions for yarn. The term yarn as used in describing the present invention is to be construed in both the specification and claims to include such textile terms as yarn, fiber, cord, strand, ribbon, tape, monofilament, multifilament and the like.

DESCRIPTION OF THE DRAWINGS FIG. I is a longitudinal cross-sectional view of a multistage, yarn-forwarding apparatus embodying features of a preferred embodiment of the present invention.

FIG. 2 is a graphical illustration of the present invention showing the suction and tension curves of a multistage yarnforwarding apparatus of the present invention.

FIG. 3 is a graphical illustration of the prior art showing the suction and tension curves of a typical single-stage yam-forwarding apparatus of the prior art.

Referring now to FIG. I, the main body of the apparatus is formed by housing unit 2 which is provided with gas inlet means 3. Housing unit 2 is hollow and the inner gas guiding surface of housing unit 2 is a series of parallel, converging, and diverging configurations with respect to the longitudinal axis of housing unit 2. Inner body 4 is inserted into housing unit 2 and is moveably positioned therein by means of mating threads 5 and 6 which are respectively located on the inner surface of housing unit 2 and the outer surface of inner body 4. Setscrew 7 is contained in housing unit 2 and contains inner body 45 thereby securing inner body 4 within housing unit 2. Inner body 3 is hollow and yarn inlet tube 8 is moveably positioned inside inner body 4. Setscrew 9 is contained in inner body 4 and contacts yarn inlet tube 8 thereby securing yarn inlet tube 8 Within inner body t. The outer surface of inner body 4 converges at surface 11 and forms annular converging chamber I2 with converging wall 13 within housing unit 2 when inner body 4 is positioned within housing unit 2. The angle of convergence of wall I3 is greater than the angle of convergence of wall Ill. The outer surface of yarn inlet tube 8 converges at surface 14 and forms annular converging chamber 15 with converging wall 16 of inner body 4 inside inner body 4i when yarn inlet tube 8 is inserted therein in an operable position. The angle of convergence of wall 16 is greater than the angle of convergence of wall M.

A gas, which is preferably air, is transferred through gas entry means 3 and enters housing unit 2 through hole 17 in housing unit 2 and passes into annular chamber i8 within housing unit 2. The gas is then free to go in two different directions. The gas can pass from annular chamber 18 into annular converging chamber 12 and then into passageway 19 within housing unit 2 and then exhaust out end 21 of housing unit 2. The gas can also pass from annular chamber I8 through holes 22, which are radially spaced around inner body 4, into annular chamber 23 inside inner body 4, then into annular converging chamber I5 and then into passageway 24. The gas then passes from passageway 24 into passageway 19 within housing unit 2 and then exhausts out end 21 of housing unit 2.

A gas seal is maintained between housing unit 2 and inner body 5 by O-ring 26 which fits in groove 27 around the circumference of inner body 4. Similarly, a gas seal is maintained between inner body 4 and yarn entry tube 8 by O-ring 28 which tits in groove 29 around the circumference of inner body 4.

In operation, yarn is fed into end 39 of yarn inlet tube 8 and passes through inlet tube 8 and connecting passageways 24 and 1& before exiting at end 21 of the above-described apparatus. A gas, which is preferably air, is passed through gas inlet means 3 and enters housing unit 2 through hole 17 in housing unit 2 and passes into annular chamber 18 within housing unit 2. A portion of the gas passes from annular chamber 118 through holes 22, which are radially spaced around inner body 5, into annular converging chamber 23, then into annular converging chamber 15 and then through annular orifice 3i into passageway 24. As the gas passes from annular converging chamber i5 into passageway 2d, the gas pressure in annular orifice 31 is reduced and the gar-1 velocity is increased, because of the restricted condition of annular orifree 33, by virtue of Bernoulli's principle which, in brief, states that minimum pressure occurs when velocity is maximum. Thus, the high-velocity gas passing through annular orifice 3i creates a low pressure or a suction at end 20 of yarn inlet tube 8 and thereby induces air to enter yarn inlet tube 8 at end 359 and pass therethrough into passageway 24. This air carries yarn 1 into yarn inlet tube 8 at end 30. The relative setting of the distance between converging wall 14 of yarn inlet tube 8 and converging wall 16 of inner body 4 can be adjusted by moving yarn inlet tube 8 inside inner body 4 to achieve a minimum pressure and thereby a maximum yarn inducing effect.

Another portion of the gas passes from annular charrzber 519 into annular converging chamber I2 and then through asunder orifice 32 into passageway 119. As the gas passes from annuiar converging chamber I2 into passageway E9, the gas pressure in annular orifice 32 is reduced and the gas velocity is increased, because of the restricted condition of annular orifice 32, by virtue of Bernoullis principle as stated above. While the gas pressure is reduced and the gas velocity is incre ad in annular orifice 32, the gas pressure is not reduced nor is the gas velocity increased as much as it is in annular orifice 3E. The relative setting of the distance between converging wall 11 of inner body 4 and converging wall 13 of housing unit 2 can be adjusted by moving inner body 4 within housing unit 2 so that maximum air velocity occurs in passageway 9 at a pressure which is approximately atmospheric. The high air velocity thereby exerts a tension on yarn I passing through chamber 19 according to the well-known formula:

T =KAL (V,,V wherein T qension K =constant L =length over which air acts A =effective surface area of yarn V =air velocity V =yarn velocity A novel feature of the present invention is that the suction effect created by gas passing through orifice 31 which induces yarn 1 into end 30 of yarn entry tube 8 and the tension force on yarn I in passageway 19 created by gas passing through orifice 32 can be independently varied by moving yarn inlet tube 8 towards or away from converging wall to thereby decreasing or increasing the cross-sectional area of annular orifice 31 and by moving inner body 4 towards or away from converging wall I3 thereby decreasing or increasing the cross-sectional area of annular orifice 32.

PREFERRED EMBODIMENTS The following examples illustrate the practice and principles of the invention and a mode of carrying out the invention. EXAMILE 1 The yam-forwarding apparatus described in FIG. it was employed to forward yarn. The run was conducted using 1300/ polyethylene terephthalate yarn with a finish running at 6,000 feet per minute through the apparatus. Air entered gas inlet 3 at a rate of about 40 s.c.f.m. at about 190 p.s.i.g. and at room temperature. Referring now to FIG. 2, the relationship of the suction effect and the tension force on the yarn is shown at various settings of inner body d within housing 2 and at an optimum setting of yarn inlet tube 8 inside inner body 4 which produced a high suction at end 2b of yarn inlet tube 8. These settings of inner body 4 within housing 2 produced various size annuli of annular orifice 32. As can be seen from tension curve 33 and suction curve 34 in FIG. 2, the apparatus of the present invention enables a high tension to be applied to the yarn in chamber I9 while at the same time ailowing a high suction to be maintained at end 2% of yarn inlet tube 8.

EXAMPLE 2 Yarn inlet tube oi the yarn-forwarding apparatus described in l was inserted all the way into inner body d tl ereby lorrning a valve seal between converging wall l4 and converging wall lid. This resulted in annular orifice 3i being closed or sealed and produced a single-stage yarn-forwarding appmatus which is typical of the prior art apparatuses. in this positioning of the apparatus, both the suction and the tension are produced by annular orifice 32 and it is impossible to independently control the suction which induces air to enter yam inlet tube and carry yarn therein and to independently control the tension exerted on the yarn by the high-velocity air passing through passageway W.

The run was conducted using 1300/190 polyethylene terephthalate yarn with a finish running at 6,000 feet per minute through the apparatus shown in H6. l and modified in this example. Air entered gas inlet 3 at a rate of about 3% s.c.f.m. at about 190 psig. and at room temperature. Referring now to 3, the relationship or" the suction effect and the tension force on the yarn is shown at various settings of inner body within housing unit 2. These settings of inner body l within housing unit Ill produce various size annular of annular orifice As can be seen in FIG. 3, as inner body 4 was moved out of housing unit 2, the size of annular orifice 32 was increased and the suction initially increased to a maximum point and then began to decrease. Similarly, as inner body l was moved out of housing unit 2, the size of annular orifice 35?. was increased and the tension force exerted on the yarn in passageway lll accordingly increased. As can be readily seen from tension curve 35 and suction curve as in H6. 3, it is impossible with a single-stage suction-tension prior art apparatus to achieve both high suction and high tension at any given size setting of critics ll claim:

ll. it yarn-forwarding apparatus which comprises:

a. a housing having an internal bore passing therethrough,

said bore being divided into sections having different diameters and connected by a converging surface;

0. a hollow element mounted in the bore of said housing and having an internal bore of different diameters connected by a converging surface, the end of said element mounted in the bore of said housing being provided with a converging outer surface having less taper than the converging surface oltho internal bore oi. said housing whereby a first annular converging chamber is formed between said converging surfaces;

c. a hollow tube mounted in the bore of said hollow element, the end of said tube mounted in the bore of said iollow element being provided with a converging outer surface having less taper than the converging surface of the internal bore of said hollow element whereby a second annular converging chamber is formed between said converging surfaces;

. inlet means for introducing a gaseous medium into the first and second annular converging chambers.

. It yarn-forwarding apparatus which comprises:

. a housing having an internal bore passing therethrough, said bore being divided into sections having difierent verging surfaces;

. a hollow tube mounted in the bore of hollow element, the end of said tube mounted in the bore of so i hollow element being provided with a conver rig outer surface having less taper than the converging .ir or the internal bore of said hollow elerne it when second annular converging chamber is u said converging surfaces;

. inlet means for introducing a gaseous medium into the first and second annular converging chambo r e. means for adjusting the position of hollow element and hollow tube to vary the crosssectional a oi" annular converging chambers, said means being separate so said hollow element and said hollow tube can ad justed in their respective positions independently.

3. A method for simultaneously imposing high suction and high tension upon a yarn to cause forwarding of said yarn which comprises introducing a yarn into a restricted area and. directing a first and a second stream of gas traveling at a high velocity upon separate portions of said yarn, said yarn traveling in a straight path, and said first and second of gas both having a converging path each of which consecutively converges with said yarn path upon contacting said yarn, without changing direction of said yarn path.

The method as described in claim wherein the "but and second streams of gas are introduced from a supply in let.

5. The method as described in claim 4 wherein the 1ntroduced at a rate of about 30 to 60 scrim. and a pi of about to 200 p.s.i.g.

6. The method as described in claim 3 wherein the velocity of the first and second streams of gas is controlled independently.

'7. The method as described in claim it wherein said first stream of gas is introduced at a rate of about ii) to 20 and at a pressure of about 80 to 200 p.s.i.g. and said second stream of gas is introduced at a rate of about 20 to 40 s.c.f.rn. and a pressure of about 80 to 200 psig.

ll. The method as described in claim El wherein the first stream of gas imposes a suction force upon the yarn and the second stream of gas imposes a tension force upon the yarn.

5 The method as described in claim ll wherein the suction force upon the yarn is about 20 to 29 inches oi mercury and the tension force upon the yarn is about 0.1 to 0.25 grams per denier.

110. The method as described in claim El wherein the rate of yarn forwarding is about 1,000 to 4,000 yards per minute.

Ill. The method as described in claim El wherein the is air. 

1. A yarn-forwarding apparatus which comprises: a. a housing having an internal bore passing therethrough, said bore being divided into sections having different diameters and connected by a converging surface; b. a hollow element mounted in the bore of said housing and having an internal bore of different diameters connected by a converging surface, the end of said element mounted in the bore of said housing being provided with a converging outer surface having less taper than the converging surface of the internal bore of said housing whereby a first annular converging chamber is formed between said converging surfaces; c. a hollow tube mounted in the bore of said hollow element, the end of said tube mounted in the bore of said hollow element being provided with a converging outer surface having less taper than the converging surface of the internal bore of said hollow element whereby a second annular converging chamber is formed between said converging surfaces; d. inlet means for introducing a gaseous medium into the first and second annular converging chambers.
 2. A yarn-forwarding apparatus which comprises: a. a housing having an internal bore passing therethrough, said bore being divided into sections having different diameters and connected by a converging surface; b. a hollow element mounted in the bore of said housing and having an internal bore of different diameters connected by a converging surface, the end of said element mounted in the bore of said housing being provided with a converging outer surface having less taper than the converging surface of the internal bore of said housing whereby a first annular converging chamber is formed between said converging surfaces; c. a hollow tube mounted in the bore of said hollow element, the end of said tube mounted in the bore of said hollow element being provided with a converging outer surface having less taper than the converging surface of the internal bore of said hollow element whereby a second annular converging chamber is formed between said converging surfaces; d. inlet means for introducing a gaseous medium into the first and second annular converging chambers; and e. means for adjusting the position of the hollow element and hollow tube to vary the cross-sectional areas of said annular converging chambers, said means being separate so said hollow element and said hollow tube can be adjusted in their respective positions independently.
 3. A method for simultaneously imposing high suction and high tension upon a yarn to cause forwarding of said yarn which comprises introducing a yarn into a restricted area and directing a first and a second stream of gas traveling at a high velocity upon separate portions of said yarn, said yarn traveling in a straight path, and said first and second streams of gas both having a converging path each of which consecutively converges with said yarn path upon contacting said yarn, without changing direction of said yarn path.
 4. The method as described in claim 3 wherein the first and second streams of gas are introduced from a single supply inlet.
 5. The method as described in claim 4 wherein the gas is introduced at a rate of about 30 to 60 s.c.f.m. and at a pressure of about 80 to 200 p.s.i.g.
 6. The method as described in claim 3 wherein the velocity of the first and second streams of gas is controlled independently.
 7. The method as described in claim 6 wherein said first stream of gas is introduced at a rate of about 10 to 20 s.c.f.m. and at a pressure of about 80 to 200 p.s.i.g. and said second stream of gas is introduced at a rate of about 20 to 40 s.c.f.m. and a pressure of about 80 to 200 p.s.i.g.
 8. The method as described in claim 3 wherein the first stream of gas imposes a suction force upon the yarn and the second stream of gas imposes a tension force upon the Yarn.
 9. The method as described in claim 8 wherein the suction force upon the yarn is about 20 to 29 inches of mercury and the tension force upon the yarn is about 0.1 to 0.25 grams per denier.
 10. The method as described in claim 3 wherein the rate of yarn forwarding is about 1,000 to 4,000 yards per minute.
 11. The method as described in claim 3 wherein the gas is air. 